Aims
Atrial fibrillation (AF) has been associated with reduced brain volume, cognitive impairment, and reduced cerebral blood flow. The causes of reduced cerebral blood flow in AF are unknown, but no reduction was seen in individuals without the arrhythmia in a previous study. The aim of this study was to test the hypothesis that brain perfusion, measured with magnetic resonance imaging (MRI), improves after cardioversion of AF to sinus rhythm (SR).
Methods and results
All patients undergoing elective cardioversion at our institution were invited to participate. A total of 44 individuals were included. Magnetic resonance imaging studies were done before and after cardioversion with both brain perfusion and cerebral blood flow measurements. However, 17 did not complete the second MRI as they had a recurrence of AF during the observation period (recurrent AF group), leaving 17 in the SR group and 10 in the AF group to complete both measurements. Brain perfusion increased after cardioversion to SR by 4.9 mL/100 g/min in the whole brain (P < 0.001) and by 5.6 mL/100 g/min in grey matter (P < 0.001). Cerebral blood flow increased by 58.6 mL/min (P < 0.05). Both brain perfusion and cerebral blood flow remained unchanged when cardioversion was unsuccessful.
Conclusion
In this study of individuals undergoing elective cardioversion for AF, restoration, and maintenance of SR for at least 10 weeks after was associated with an improvement of brain perfusion and cerebral blood flow measured by both arterial spin labelling and phase contrast MRI. In those individuals where cardioversion was unsuccessful, there was no change in perfusion or blood flow.
Cardiac myxoma (CM) is the most common primary benign tumor of the heart, but the true age-standardized incidence rate (ASR) has remained unknown. We therefore used nationwide registries in Iceland to study CM and establish its incidence rate. This was a retrospective study involving all patients diagnosed with CM in Iceland between 1986 and 2010. Cases were identified through three different registries, and hospital charts and histology results reviewed. An ASR was estimated based on a world standard population (w). Nine cases of CM (six women) were identified with a mean age of 62.8 years (range: 37-85), giving an ASR of 0.11 (95% CI: 0.05-0.22) per 100,000. The mean tumor size was 4.4 cm (range: 1.5-8.0) with all the tumors located in the left atrium. Dyspnea (n = 6) and ischemic stroke (n = 2) were the most common symptoms. All patients underwent complete resection of the tumor and there were no postoperative deaths or CM-related deaths at follow-up (mean 85 months). The ASR of CM in Iceland was 0.11 per 100,000. To our knowledge, this is the first study to determine the incidence of CM in an entire population. In Iceland, the presenting symptoms and mode of detection of CM are similar to those in other series.
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